Paul Scherrer Institut, Switzerland
Title: Adsorbent materials for desulfurization processes under supercritical water conditions
Biography: Florentina Maxim
Statement of the Problem: It is recognized that the great technological potential of the catalytic super critical water (SCW) gasification of biomass for biofuel production. However, an important issue related to the poisoning of the catalyst by sulfur (S) compounds remaining in the SCW phase is still to be solved. To design efficient S adsorbents at SCW conditions is a challenge since, the sorbent material, which is sought as metal oxide (MexOy), must be structurally stable and in the same time to be able to capture S from both inorganic and organic sources under SCW conditions. The purpose of this work is to design and obtain supported nano MexOy adsorbent materials for efficient desulfurization in SCW. Our previous results reported on the impact of sorbent geometry on the S adsorption in SCW.
Materials & Methodology: SCW impregnation of MexOy (ZnO, CuO, Mn2O4, Fe2O3) on activated carbon was performed in a continuous flow tubular reactor (Figure), also used for S sorption experiments. In situ neutron imaging (NI), molecular dynamics (MD) and computational fluid dynamics (CFD) were the main techniques used to obtain fundamental knowledge on the phenomena taking place when different S species are adsorbed by MexOy in SCW.
Findings: The NI results, reporting on the S in SCW density profiles and flow patterns through the adsorbent were used for the validation of models applied in MD and CFD. The SCW desulfurization efficiency of different MexOy was established.
Conclusion & Significance: The findings of the present study are of great importance when the goal is to mitigate the deactivation of the catalyst by S from the foregoing biomass gasification by SCW.